How to Choose the Right Sealed Airspace for Your Subwoofer Enclosure

The Importance of Air Space for Subwoofers

Selecting the right sealed airspace for your subwoofer enclosure is essential for achieving optimal sound quality and performance. The size of the enclosure directly influences the subwoofer’s frequency response, power handling, and overall output. Whether you're aiming for tight, punchy bass or deeper, more resonant low-end tones, understanding how airspace impacts these factors is key to making an informed choice. In this guide, we’ll explore the relationship between enclosure size, sound preference, and power handling, helping you choose the perfect setup for your audio system.

1. Subwoofer Specifications

• Recommended Airspace: Always start by checking the manufacturer’s recommended airspace for the subwoofer. This is typically given in cubic feet (ft³). Staying within the recommended range helps ensure the subwoofer performs as designed.

2. Sound Preference

• Tight Bass (Smaller Enclosure-increased power handling): A smaller sealed enclosure generally results in tighter, more precise bass. This is great for those who want accuracy, especially with fast or complex bass lines (common in genres like rock or jazz).
• Deep Bass (Larger Enclosure-decreased power handling): A slightly larger sealed enclosure allows for more bass extension, producing a deeper, fuller sound. If you're into music genres with a lot of low-end bass (like hip hop or electronic music), you might prefer this.

 

How Airspace affects Frequency Response

The size of the sealed enclosure significantly impacts the subwoofer’s frequency response. As shown in the image:

• Red Line (1 ft³ Airspace): This larger airspace extends the subwoofer’s ability to produce lower frequencies, giving a deeper bass response.
• Blue Line (0.7 ft³ Airspace): A mid-sized enclosure offers a balance between tightness and depth.
• Green Line (0.5 ft³ Airspace): This smaller airspace provides a tighter bass response, with more punch but less low-end extension.

The differences in frequency response across these airspaces confirm the theory that larger enclosures emphasize deeper frequencies. However, as illustrated, these changes are noticeable but not dramatic within typical airspace ranges.

Power vs. Excursion

Power handling is directly affected by enclosure size. The graph below illustrates how much power it takes for the subwoofer in each enclosure to reach its 14mm excursion limit (the point at which the subwoofer cone can no longer travel further without risking damage):

• Red Line (250 watts): In the largest enclosure (1 ft³), the subwoofer reaches its excursion limit at lower power, meaning less power handling before hitting its mechanical limits.
• Blue Line (350 watts): The mid-sized enclosure allows for more power handling compared to the larger one.
• Green Line (500 watts): The smallest enclosure (0.5 ft³) handles the most power before reaching the subwoofer’s excursion limit.

As the enclosure size decreases, the subwoofer’s ability to handle more power increases, but at the cost of lower bass extension. This is an important consideration when matching the enclosure to your amplifier and musical preferences.

Maximum Output

Finally, let’s look at how enclosure size affects the overall output. In the comparison below, we see the subwoofer’s maximum loudness across the different airspaces:

• The 1 ft³ enclosure provides deeper bass but reaches its output limits at lower power.
• The 0.7 ft³ enclosure strikes a balance, offering moderate depth and output.
• The 0.5 ft³ enclosure can play the loudest but sacrifices some low-end frequency response for this added output.

In conclusion, choosing the right airspace for your subwoofer depends on your balance between sound preference, power handling, and available space. Larger enclosures provide more bass extension, while smaller ones offer more precision and increased power handling.